CKEDITOR.plugins.add('insertcode',  
  {   
    requires: ['dialog'],     
    init:function(a) {  
      a.addCommand('insertcode',new CKEDITOR.dialogCommand('insertcode'));  
      a.ui.addButton('insertcode',  
                     {label:a.lang.insertcode.toolbar,command:'insertcode',icon:this.path+'images/code.gif'}  
                     );  
      CKEDITOR.dialog.add('insertcode',this.path+'dialogs/insertcode.js');  
    }  
  }  
);